Processing method of battery shell

Abstract

The invention relates to the technical field of batteries, particularly provides a treatment method of a battery shell, and aims to solve the problem that the effect of connecting and sealing the battery shell by adopting a laser welding mode in the prior art is poor. Therefore, the invention provides a processing method of a battery shell, which comprises the following steps of: forming a first groove in a connecting part of the battery shell; and a plastic frame which is partially accommodated in the first groove and covers the outer end face of the connecting part is formed on the connecting part through injection molding. The plastic frame partially accommodated in the first groove is formed on the connecting part of the battery shell through injection molding, so that the stable connection of the battery shell can be realized, the sealing performance is good, the yield is high, injection molding sealing can be simultaneously carried out on a large scale, in addition, the binding force of the plastic frame and the shell can be improved, and the structural strength and the sealing effect of the shell are further improved.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and particularly provides a method for processing a battery housing. Background Art

[0002] New energy vehicles have received increasing attention due to their characteristics such as low noise, pollution-free, and high energy efficiency, thus promoting the accelerated development of new energy vehicles. Currently, new energy vehicles usually use batteries as the power source, which provides a broad space for the application and development of lithium-ion batteries.

[0003] The housing of the existing battery uses laser welding to achieve the connection and sealing of the battery housing. However, laser welding generally has problems of low welding yield and unsatisfactory sealing effect.

[0004] Therefore, a new technical solution is needed in this field to solve the above problems. Summary of the Invention

[0005] The present invention aims to solve the above technical problems, that is, to solve the problem of poor connection and sealing effects of the battery housing by using laser welding in the prior art.

[0006] In a first aspect, the present invention provides a method for processing a battery housing, including the following steps: Step 1: Set a first groove at the connection part of the battery housing; Step 2: Inject plastic on the connection part to form a plastic frame that is partially received in the first groove and covers the outer end face of the connection part.

[0007] In a preferred technical solution of the above method for processing a battery housing, Step 1 specifically includes: setting a first groove at the connection part of the battery housing by laser.

[0008] In a preferred technical solution of the above method for processing a battery housing, simultaneously with Step 1, the processing method further includes: cleaning the dust generated on the connection part.

[0009] In a preferred technical solution of the above method for processing a battery housing, the battery housing includes a first outer shell, a partition board, and a second outer shell arranged along the thickness direction, the connection part includes a first connection part provided on the first outer shell and a second connection part provided on the second outer shell, and Step 1 specifically includes: setting a first groove on the first connection part and / or the second connection part by laser.

[0010] In a preferred technical solution of the above method for processing a battery housing, before, after, or simultaneously with Step 1, the processing method further includes the following step: setting a second groove on the partition board by laser for receiving a part of the plastic frame.

[0011] In a preferred technical solution of the above battery housing processing method, before step two, the processing method further includes the following steps: fixedly connecting the first housing, the partition plate, and the second housing by laser spot welding.

[0012] In a preferred technical solution of the above battery housing processing method, the depth of the first groove is any value from 10 microns to 290 microns; and / or, the width of the first groove is any value from 20 microns to 200 microns; and / or, the first groove forms a ring along the circumferential direction of the battery housing; and / or, the number of the first grooves is multiple and they are distributed at intervals.

[0013] In a preferred technical solution of the above battery housing processing method, step two specifically includes: placing the assembled battery into an injection mold; heating and melting the injection material and then injecting it into the injection mold to form a plastic frame on the connection part of the battery housing.

[0014] In a preferred technical solution of the above battery housing processing method, before the step of "heating and melting the injection material and then injecting it into the injection mold", the processing method further includes: preheating the injection mold.

[0015] In a preferred technical solution of the above battery housing processing method, the step of "heating and melting the injection material and then injecting it into the injection mold" specifically includes: injecting the molten injection material into the injection mold in a high-pressure jet manner.

[0016] In the case of adopting the above technical solution, the present invention connects and seals the housing of the battery by injection molding, with high connection strength, good sealing performance and high yield. Moreover, it can perform mass injection sealing simultaneously. After injection molding, the injection material forms a plastic frame on the connection part of the housing. The plastic frame has a strong bonding force with the housing. And the connection between the plastic frame and the housing can be disassembled without damage by physical methods, which is convenient for the recycling and reuse of the housing. In addition, the present invention also forms a first groove on the connection part of the housing. During the injection molding process, the molten plastic will penetrate into the first groove of the connection part, thereby improving the bonding force between the plastic frame and the housing and further enhancing the sealing effect on the housing.

[0017] Furthermore, the present invention processes the connection part by laser to form the first groove, with high processing efficiency, and can accurately ensure the size of the first groove, and can control the size of the first groove at the micron level. It can not only significantly enhance the connection strength between the plastic frame and the connection part, but also effectively ensure the sealing effect on the housing of the battery, and is convenient for processing, with low cost and simple operation.

[0018] Furthermore, the present invention also processes the partition of the housing to form a second groove on the partition, which can further improve the connection stability between the plastic frame and the partition, thereby further improving the sealing effect of the housing.

[0019] Furthermore, the present invention also fixes the first housing, the partition and the second housing of the battery together by laser spot welding, which can prevent the housing of the battery from cracking during the injection molding process, thereby facilitating the guarantee of the sealing effect of the housing of the battery.

[0020] Furthermore, by limiting the depth of the first groove, the present invention can avoid affecting the bonding force between the plastic frame and the housing due to the too shallow depth of the first groove, and can also avoid affecting the structural strength of the connecting part due to the too deep depth of the first groove; by setting the first groove to be strip-shaped, the present invention is convenient for the processing of the first groove and can also increase the contact area between the plastic frame and the housing, thereby improving the bonding force between the plastic frame and the housing; by making the first groove surround the housing in a circumferential direction to form a ring, the present invention can not only improve the bonding force between the plastic frame and the housing, but also improve the sealing effect of the housing.

[0021] Furthermore, before injecting the injection molding material into the injection mold, the present invention preheats the injection mold first, which is beneficial to the full filling of the plastic filling area of the injection mold by the injection molding material, thereby improving the sealing performance of the housing of the battery.

[0022] Furthermore, by adopting the method of high-pressure spraying to inject the molten injection molding material into the injection mold, the present invention is beneficial to the full filling of the plastic filling area of the injection mold by the injection molding material, thereby improving the sealing performance of the housing of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings, in which:

[0024] Figure 1 is an exploded schematic view of the battery housing assembly of the present invention;

[0025] Figure 2 is a schematic structural view of the battery housing assembly of the present invention;

[0026] Figure 3 is Figure 2 a cross-sectional view taken along line A-A in

[0027] Figure 4 is a schematic structural view of the first embodiment of the battery housing of the present invention;

[0028] Figure 5 is a schematic structural view of the second embodiment of the battery housing of the present invention;

[0029] Figure 6 It is a schematic structural diagram of the third embodiment of the battery housing of the present invention;

[0030] Figure 7 It is a schematic structural diagram of the first embodiment of the connecting portion of the battery housing of the present invention;

[0031] Figure 8 It is a schematic structural diagram of the second embodiment of the connecting portion of the battery housing of the present invention;

[0032] Figure 9 It is a flowchart of the processing method of the battery housing of the present invention;

[0033] Figure 10 It is a schematic diagram of the first outer shell of the battery of the present invention installed on the tooling;

[0034] Figure 11 It is a schematic diagram of the housing of the battery of the present invention installed in the injection mold.

[0035] List of reference numerals:

[0036] 1. Battery housing; 11. First outer shell; 12. Second outer shell; 13. Partition; 14. Connecting portion; 15. First groove; 141. First connecting portion; 142. Second connecting portion; 131. Second groove;

[0037] 2. Plastic frame;

[0038] 3. Tooling; 31. Dust removal channel;

[0039] 4. Injection mold; 41. Upper mold; 42. Lower mold; 43. Plastic filling area. Detailed implementation manners

[0040] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principle of the present invention and are not intended to limit the protection scope of the present invention.

[0041] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. Those skilled in the art should understand that in the description of the present invention, although the steps of the processing method of the present invention are described in a specific order, these orders are not restrictive. Without departing from the basic principle of the present invention, those skilled in the art can execute the steps in a different order.

[0042] It should be noted that in the description of the present invention, the terms "inner", "outer", "upper", "lower", "left", "right" and other terms indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings. This is only for convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, so it should not be construed as a limitation of the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0043] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "set", "connected", "installed" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0044] Specifically, the present invention provides a method for processing a battery case. As Figure 1 shown, the battery case 1 has a connecting portion 14. The processing method of the present invention includes the following steps:

[0045] Step 1: Set a first groove 15 in the connecting portion of the battery case (see Figure 3 );

[0046] Step 2: Injection mold a plastic frame 2 on the connecting portion, which is partially received in the first groove and covers the outer end face of the connecting portion (see Figure 3 ). Specifically:

[0047] Process the surface of the connecting portion 14 of the battery case so as to form a first groove 15 on the surface of the connecting portion 14 that can accommodate the injection molding material;

[0048] Injection mold the battery case 1 to form a plastic frame 2 covering the outer end face of the connecting portion 14.

[0049] Among them, the step of "injection molding the battery case" preferably includes:

[0050] Put the assembled battery into an injection mold 4 (see Figure 11 );

[0051] Heat and melt the injection molding material and then inject it into the injection mold 4 to form a plastic frame 2 covering the outer end face of the connecting portion 14 of the battery case 1.

[0052] That is to say, in the present invention, an injection molding method is adopted to form a plastic frame 2 covering the outer end surface at the connection part 14 of the battery case 1. Compared with the prior art in which the battery case is connected and sealed by laser welding, the injection molding method has higher connection strength, better sealing performance and higher yield. Moreover, it is possible to perform injection molding and sealing in large batches simultaneously, with high efficiency and low cost. After the injection molding and sealing are completed, the injection molding material forms a plastic frame 2 on the battery case 1 (see Figure 1 ). The plastic frame 2 and the battery case 1 form the housing assembly of the battery. In addition, the connection between the plastic frame 2 and the battery case 1 can be disassembled without damage through physical methods (such as heating), which is convenient for the recycling and reuse of the battery case 1.

[0053] Such as Figures 1 to 3 shown, after the connection part 14 of the battery case 1 is processed, a first groove 15 for accommodating the injection molding material (such as plastic) will be formed on the surface of the connection part 14 connected to the plastic frame 2.

[0054] After the injection molding is completed, the plastic frame 2 formed by the injection molding material covers the outer end surface of the connection part 14 to achieve the connection and sealing of the battery case 1. By providing the first groove 15 on the surface of the connection part 14, during the injection molding process, the molten plastic will penetrate into the first groove 15 of the connection part 14, thereby improving the bonding force between the plastic frame 2 and the battery case 1. Among them, the battery case 1 is made of metal, preferably an aluminum shell.

[0055] Exemplarily, as Figures 1 to 3 shown, the connection part 14 on the battery case 1 is arranged in a circle along the circumferential direction of the battery case 1, and the plastic frame 2 is also arranged in a circle along the circumferential direction of the battery case 1. The plastic frame 2 is made of plastic. During the processing, first, the assembled battery is placed into the injection mold 4, and then the molten plastic is injected into the injection mold 4. After the plastic cools, a plastic frame 2 is formed in a circle along the circumferential direction of the battery case 1.

[0056] Preferably, in step one, the step of "providing a first groove at the connection part of the battery case" specifically includes: providing a first groove at the connection part of the battery case by laser.

[0057] Exemplarily, first, the laser processing path is set through the processing software of the laser processing equipment, and the laser emits light for processing according to the set laser processing path through galvanometer scanning to form the first groove 15 on the surface of the connection part 14.

[0058] It should be noted that the present invention does not limit the specific type of the laser processing equipment. For example, a continuous wave laser processing equipment or a pulsed laser processing equipment can be used, as long as the laser processing equipment can process a groove on the surface of the connection part 14 that can accommodate the injection molding material.

[0059] Preferably, while performing the step of "setting a first groove at the connection part of the battery case by laser", the processing method of the present invention further includes: cleaning the dust generated on the connection part. Specifically, it is to clean the metal dust generated on the connection part 14 during the laser processing.

[0060] During the processing of the connection part 14 of the battery case 1 by a laser processing device, metal dust will be generated on the connection part 14. By turning on the dust removal device and timely sucking away the metal dust generated on the connection part 14, it is possible to avoid the phenomenon of the metal dust scattering the laser, thereby ensuring the stability and accuracy of the size of the first groove 15.

[0061] Preferably, as Figures 1 to 3 shown, the battery case 1 of the present invention includes a first outer shell 11, a partition 13, and a second outer shell 12 arranged in the thickness direction. The connection part 14 includes a first connection part 141 provided on the first outer shell 11 and a second connection part 142 provided on the second outer shell 12. The step of "setting a first groove at the connection part of the battery case by laser" specifically includes: setting a first groove on the first connection part and / or the second connection part by laser.

[0062] That is to say, as Figure 3 shown, the first connection part 141 is provided with a first groove 15 on the surface connected to the plastic frame 2, and the second connection part 142 is also provided with a first groove 15 on the surface connected to the plastic frame 2.

[0063] Exemplarily, as Figures 1 to 3 shown, the first connection part 141 and the second connection part 142 are respectively arranged in a circle along the circumferences of the first outer shell 11 and the second outer shell 12. The upper surface and the lower surface of the first connection part 141 are both provided with the first groove 15. There is a gap between the lower surface of the first connection part 141 and the partition 13. The lower surface and the upper surface of the second connection part 142 are also both provided with the first groove 15. There is also a gap between the upper surface of the second connection part 142 and the partition 13. The plastic frame 2 completely covers the first connection part 141 and the second connection part 142, and seals the space between the first connection part 141 and the partition 13 and the space between the second connection part 142 and the partition 13.

[0064] It should be noted that those skilled in the art can, in practical applications, only provide the first groove 15 on the upper surface of the first connecting portion 141 and the lower surface of the second connecting portion 142, and at the same time make the lower surface of the first connecting portion 141 fit with the top surface of the partition plate 13 and the upper surface of the second connecting portion 142 fit with the bottom surface of the partition plate 13. Or, the surface of the first connecting portion 141 or the surface of the second connecting portion 142 can also be processed by a laser processing device, that is, the first groove 15 is only provided on the surface of the first connecting portion 141 or the surface of the second connecting portion 142, etc. Such flexible adjustments and changes do not deviate from the principle and scope of the present invention and should all be defined within the protection scope of the present invention. Of course, the present invention preferably provides the first groove 15 on both the first connecting portion 141 and the second connecting portion 142.

[0065] In addition, it should also be noted that the battery housing 1 of the present invention is not limited to the above-mentioned structural form of "the first housing 11 + the partition plate 13 + the second housing 12". For example, the battery housing 1 can also be set into the structural form of a traditional "housing main body + cover plate". Of course, the present invention preferably sets the battery housing 1 into the above-mentioned structural form of "the first housing 11 + the partition plate 13 + the second housing 12". A chamber for accommodating the battery cell can be formed between the first housing 11 and the partition plate 13, and a chamber for accommodating the battery cell can also be formed between the second housing 12 and the partition plate 13. In this way, the battery housing 1 can accommodate two battery cells at the same time.

[0066] Preferably, before, after or at the same time as the step of "providing the first groove in the connecting portion of the battery housing by laser", the processing method of the present invention further includes the following steps: providing a second groove for accommodating part of the plastic frame on the partition plate by laser. Specifically: the partition plate 13 is processed by laser so as to form a second groove 131 capable of accommodating the injection molding material at the positions corresponding to the first connecting portion 141 and the second connecting portion 142 on the partition plate 13.

[0067] That is to say, as Figure 3 shown, the partition plate 13 of the present invention is provided with second grooves 131 for accommodating the injection molding material at the positions corresponding to the first connecting portion 141 and the second connecting portion 142.

[0068] By providing the second groove 131 on the partition plate 13, the connection area between the plastic frame 2 and the battery housing 1 can be increased, thereby improving the connection stability between the plastic frame 2 and the battery housing 1.

[0069] It should be noted that those skilled in the art can, in actual applications, process only the position of the partition 13 corresponding to the first connecting portion 141 through a laser processing device, that is, the partition 13 is provided with a second groove 131 only at the position corresponding to the first connecting portion 141, or can also process only the position of the partition 13 corresponding to the second connecting portion 142 through a laser processing device, that is, the partition 13 is provided with a second groove 131 only at the position corresponding to the second connecting portion 142. Such flexible adjustment and change do not deviate from the principle and scope of the present invention and should be limited within the protection scope of the present invention. Of course, the present invention preferably provides the second groove 131 at the positions of the partition 13 corresponding to both the first connecting portion 141 and the second connecting portion 142.

[0070] Preferably, before the step of "injecting plastic to form a plastic frame partially received in the first groove and covering the outer end face of the connecting portion on the connecting portion", the processing method of the present invention further includes the following steps: fixing the first housing 11, the partition 13 and the second housing 12 of the battery together by laser spot welding.

[0071] That is to say, before putting the assembled battery into the injection mold 4, first fixing the first housing 11, the partition 13 and the second housing 12 of the battery together by laser spot welding can prevent the battery housing 1 from cracking during the injection molding process, thus being beneficial to ensuring the sealing effect of the battery housing 1.

[0072] Preferably, step two, "injecting plastic to form a plastic frame partially received in the first groove and covering the outer end face of the connecting portion on the connecting portion" is specifically: putting the assembled battery into the injection mold; heating and melting the injection material and then injecting it into the injection mold to form a plastic frame covering the outer end face of the connecting portion on the connecting portion of the battery housing.

[0073] Before the step of "heating and melting the injection material and then injecting it into the injection mold", the processing method further includes: preheating the injection mold.

[0074] Preferably, the step of "heating and melting the injection material and then injecting it into the injection mold" specifically includes: injecting the molten injection material into the injection mold in a high-pressure jet manner.

[0075] By injecting the molten injection material into the injection mold 4 in a high-pressure jet manner, it is beneficial to fully fill the plastic filling area 43 of the injection mold 4 (see Figure 11 ) and thus improve the connection and sealing effect on the battery housing 1.

[0076] Exemplarily, the material to be injection-molded can be heated and melted through the heating system of an injection molding machine, and then the molten injection material can be injected into the injection mold 4 through the injection pressure system.

[0077] Preferably, before the step of "heating and melting the injection molding material and then injecting it into the injection mold 4", the processing method of the present invention further includes: preheating the injection mold 4.

[0078] Preheating the injection mold 4 before injecting the injection molding material into the injection mold 4 is beneficial to fully filling the plastic filling area 43 of the injection mold 4 with the injection molding material, thereby improving the sealing performance of the battery case 1.

[0079] Exemplarily, the injection mold 4 can be preheated through the heating system of the injection molding machine.

[0080] It should be noted that those skilled in the art can set a preheating time in actual applications. When the preheating time of the injection mold 4 reaches the preheating time, start injecting the injection molding material into the injection mold 4. Or, a set temperature can also be set. When the temperature of the injection mold 4 reaches the set temperature, start injecting the injection molding material into the injection mold 4, etc. Such flexible adjustments and changes do not deviate from the principle and scope of the present invention and should all be limited within the protection scope of the present invention.

[0081] Preferably, the step of "preheating the injection mold 4" specifically includes: preheating the injection mold 4 to a set temperature.

[0082] Exemplarily, the set temperature is 100 °C. The injection molding machine heats the injection mold 4 through the heating system. When the temperature of the injection mold 4 reaches 100 °C, start injecting the injection molding material into the injection mold 4.

[0083] It should be noted that the value of the set temperature is not limited to the above 100 °C. For example, the set temperature can also be set to 50 °C, 80 °C, 150 °C or 200 °C, etc. Those skilled in the art can flexibly set the specific value of the set temperature according to the type of the injection molding material through experiments or experience in actual applications.

[0084] Among them, it is preferred to set the set temperature to 50 °C to 200 °C, and more preferably to 80 °C to 100 °C.

[0085] Taking the battery case 1 including the first outer shell 11, the second outer shell 12 and the partition 13 as an example, the optimal embodiment of the processing method of the battery case of the present invention will be introduced in detail below.

[0086] As Figure 9 shown, the processing method of the present invention includes the following six steps:

[0087] S100: Processing the surface of the connecting portion 14 through a laser processing device so as to form a first groove 15 capable of accommodating the injection molding material on the surface of the connecting portion 14.

[0088] Exemplarily, as Figure 10 shown, when processing the connecting portion 14 of the battery case 1 by a laser processing device, the first outer shell 11 and the second outer shell 12 are respectively installed on the tooling 3, and the first outer shell 11 and the second outer shell 12 are fixed by the tooling 3 to prevent displacement of the first outer shell 11 and the second outer shell 12 during the processing. A dust removal channel 31 is provided on the tooling 3, and a dust removal device (such as a vacuum cleaner) is communicated with the dust removal channel 31. During the processing, the metal dust generated during the processing is sucked away by the dust removal device.

[0089] It should be noted that, as Figures 4 to 6 shown, the first groove 15 is preferably set to be strip-shaped, which is not only convenient for the processing of the first groove 15, but also can increase the contact area between the plastic frame 2 and the connecting portion 14 of the battery case 1, thereby improving the bonding force between the plastic frame 2 and the battery case 1; and, preferably, the first groove 15 extends along the length direction of the connecting portion 14, and the first groove 15 forms a ring along the circumferential direction of the battery case 1. By making the first groove 15 form a closed loop along the circumferential direction of the battery case 1, it can not only improve the bonding force between the plastic frame 2 and the battery case 1, but also improve the sealing effect on the battery case 1.

[0090] Example 1, as Figure 4 shown, the battery case 1 is a rectangular structure, and the battery case 1 has two long sides and two short sides. Correspondingly, both the first connecting portion 141 and the second connecting portion 142 are composed of two long-side connecting portions and two short-side connecting portions. The first groove 15 on the long-side connecting portion extends along the length direction of the long-side connecting portion (i.e., the length direction of the battery case 1) and penetrates the long-side connecting portion, and the first groove 15 on the short-side connecting portion extends along the length direction of the short-side connecting portion (i.e., the width direction of the battery case 1) and penetrates the short-side connecting portion. In this way, the two ends of the first groove 15 on the long-side connecting portion are respectively communicated with the first groove 15 on the corresponding short-side connecting portion, and the two ends of the first groove 15 on the short-side connecting portion are respectively communicated with the first groove 15 on the corresponding long-side connecting portion, so that the first groove 15 forms a ring along the circumferential direction of the battery case 1.

[0091] Example 2, as Figure 5 shown, the ring formed by the first groove 15 is rectangular. That is to say, the first groove 15 on the long-side connecting portion and the first groove 15 on the short-side connecting portion are connected end to end to form a rectangular closed path.

[0092] Example 3, as Figure 6As shown, the ring formed by the first groove 15 is rectangular, and the four corners of the ring are all set as rounded corners. By setting the four corners of the ring formed by the first groove 15 as rounded corners, it is beneficial to both the processing of the first groove 15 and the flow of the injection molding material along the first groove 15, so as to completely fill the entire ring-shaped first groove 15.

[0093] In addition, it should also be noted that, as Figures 4 to 6 shown, the number of the first grooves 15 is preferably set to be multiple, and the multiple first grooves 15 are spaced apart along the direction away from the battery housing 1.

[0094] Example 1, as Figure 4 shown, each first groove 15 penetrates through the connecting portion 14 along the length direction of the connecting portion 14. In the four right-angle range areas of the connecting portion 14, the first grooves 15 on the long-side connecting portion intersect with the first grooves 15 on the short-side connecting portion, having an overlapping area.

[0095] Example 2, as Figure 5 shown, a plurality of rectangular ring grooves are provided on the connecting portion 14, and the plurality of ring grooves are arranged in an array. Along the direction away from the battery housing 1 (i.e., from the inside to the outside), the length of the ring groove gradually increases.

[0096] As Figure 7 and Figure 8 shown, in the case where a plurality of first grooves 15 are provided, it is preferable to make the plurality of first grooves 15 evenly spaced. Among them, the groove spacing d between two adjacent first grooves 15 is preferably any value between 30 micrometers and 300 micrometers.

[0097] Among them, the groove spacing d between two adjacent first grooves 15 is the distance between the center lines of the two first grooves 15.

[0098] By setting the groove spacing within the above range, on the one hand, it can prevent the number of the first grooves 15 from being too small due to too large a groove spacing, which affects the connection strength and sealing effect of the housing. On the other hand, it can prevent the number of the first grooves 15 from being too large due to too small a groove spacing, which affects the structural strength of the connecting portion 14 and reduces the processing efficiency. Therefore, the setting of the above groove spacing can ensure the processing efficiency and the structural strength and sealing effect of the battery while ensuring the structural strength of the connecting portion.

[0099] Exemplarily, the groove spacing d can be set to 30 micrometers, 50 micrometers, 100 micrometers, 150 micrometers, 200 micrometers, 250 micrometers or 300 micrometers. Among them, the groove spacing d between two adjacent first grooves 15 is further preferably set to any value between 100 micrometers and 200 micrometers.

[0100] As Figure 7 and Figure 8As shown, the width a of the first groove 15 is preferably any value from 20 micrometers to 200 micrometers.

[0101] Exemplarily, the width a of the first groove 15 can be set to 20 micrometers, 50 micrometers, 80 micrometers, 100 micrometers, 120 micrometers, 150 micrometers, 180 micrometers or 200 micrometers. Among them, the width a of the first groove 15 is further preferably set to any value from 50 micrometers to 120 micrometers.

[0102] It should be noted that in the case where there are multiple first grooves 15, it is preferred to set the widths of the multiple first grooves 15 to be the same.

[0103] The above setting of the groove width can, on the one hand, prevent the groove width from being too small, which affects the efficiency of the molten plastic flowing into the first groove 15 and also affects the connection strength between the plastic frame 2 and the connecting portion 14. On the other hand, it can prevent the groove width from being too large and affecting the structural strength of the connecting portion 14. Therefore, the setting of the above parameter range can, on the one hand, ensure the structural strength of the connecting portion 14 and, on the other hand, ensure the processing efficiency.

[0104] As Figure 7 and Figure 8 shown, the depth of the first groove 15 is preferably any value from 10 micrometers to 290 micrometers.

[0105] Exemplarily, those skilled in the art can set the depth of the first groove 15 to 10 micrometers, 50 micrometers, 100 micrometers, 150 micrometers, 200 micrometers, 250 micrometers or 290 micrometers in practical applications.

[0106] It should be pointed out that the depth of the first groove 15 refers to the dimension of the first groove 15 along the thickness direction of the connecting portion 14. By limiting the depth of the first groove 15, it can avoid affecting the bonding force between the plastic frame 2 and the battery housing 1 due to the too shallow depth of the first groove 15, and can also avoid affecting the structural strength of the connecting portion 14 due to the too deep depth of the first groove 15. Among them, the depth of the first groove 15 is further preferably any value from 50 micrometers to 150 micrometers.

[0107] The above setting of the groove depth range can, on the one hand, prevent the groove depth from being too large and resulting in a reduction in the strength of the connecting portion 14, and on the other hand, prevent the groove depth from being too small and resulting in a reduction in the connection strength between the plastic frame 2 and the connecting portion 14 and a decrease in the sealing effect. Therefore, the above setting of the groove depth range can, on the one hand, ensure the structural strength of the connecting portion 14 and, on the other hand, ensure the connection strength between the connecting portion 14 and the plastic frame 2 and the sealing effect.

[0108] In the first preferred example, as Figure 7As shown, the number of the first grooves 15 is set to be multiple, and the multiple first grooves 15 are spaced apart along the width direction of the connecting portion 14. Among them, the depths h of the multiple first grooves 15 are all the same. The depth h of the first groove 15 is preferably any value from 10 microns to 290 microns, and further preferably any value from 50 microns to 150 microns.

[0109] In the second preferred example, as Figure 8 shown, the number of the first grooves 15 is set to be multiple, and the multiple first grooves 15 are spaced apart along the direction away from the battery housing 1. Among them, the depth of the first groove 15 close to the battery housing 1 is less than the depth of the first groove 15 away from the battery housing 1.

[0110] That is to say, in the case where there are multiple first grooves 15, the depths of the first grooves 15 are not the same. The depth of the first groove 15 on the side close to the battery housing 1 (seen from Figure 8 above as the left side of the connecting portion 14) is small, and the depth of the first groove 15 on the side away from the battery housing 1 (seen from Figure 8 above as the right side of the connecting portion 14) is large. Through such a setting, it is possible to avoid the situation that the first groove 15 on the side close to the battery housing 1 cannot be filled with the injection molding material, which is beneficial to ensuring the structural strength of the connecting portion 14.

[0111] Exemplarily, as Figure 8 shown, the multiple first grooves 15 are composed of multiple shallow grooves and multiple deep grooves. The shallow grooves are arranged close to the battery housing 1, and the deep grooves are arranged away from the battery housing 1. The depth of the shallow grooves is less than the depth of the deep grooves. Among them, the shallow grooves are located inside the connecting portion 14 (seen from Figure 8 above as the left side of the connecting portion 14), and the deep grooves are located outside the connecting portion 14 (seen from Figure 8 above as the right side of the connecting portion 14).

[0112] As Figure 8 shown, the depth hi of the shallow grooves is preferably set to any value from 20 microns to 40 microns, and the depth hs of the deep grooves is preferably set to any value from 100 microns to 120 microns.

[0113] For example, the depth hi of the shallow grooves can be set to 20 microns, 25 microns, 30 microns, 35 microns or 40 microns; the depth hs of the deep grooves can be set to 100 microns, 105 microns, 110 microns, 115 microns or 120 microns.

[0114] It should be noted that except for the different depths, the widths and the groove spacings of the shallow grooves and the deep grooves are preferably set to be the same.

[0115] S200: Process the partition 13 with a laser processing device so as to form a second groove 131 capable of accommodating injection molding material at positions corresponding to the first connecting portion 141 and the second connecting portion 142 on the partition 13.

[0116] Similar to processing the first groove 15 on the connecting portion 14, when processing the partition 13, it is also necessary to install the partition 13 on the tooling 3, fix the partition 13 through the tooling 3, and during the processing, turn on the dust removal device to suck away the metal dust generated on the partition 13.

[0117] It should be noted that the second groove 131 is also preferably set to be strip-shaped and provided with multiple ones. Among them, the first groove 15 can be set parallel to the second groove 131, or the first groove 15 can be set to intersect with the second groove 131, etc. Such flexible adjustment and change do not deviate from the principle and scope of the present invention and should all be limited within the protection scope of the present invention.

[0118] In addition, the width, depth, and groove spacing of the second groove 131 can all be set with reference to the first groove 15.

[0119] S300: Fix the first housing 11, the partition 13, and the second housing 12 together by laser spot welding.

[0120] After the first housing 11, the second housing 12, and the partition 13 are processed by the laser processing device, start assembling the battery. Install two battery cells in the battery housing 1, then fix the first housing 11, the partition 13, and the second housing 12 together by laser spot welding, and then put the assembled battery into the injection molding die 4. In this way, it is possible to prevent the battery housing 1 from cracking during the injection molding process, which is beneficial to ensuring the sealing effect of the battery housing 1.

[0121] S400: Put the assembled battery into the injection molding die 4.

[0122] As Figure 11 shown, the injection molding die 4 includes an upper die 41 and a lower die 42. After the die is closed, the upper die 41 and the lower die 42 respectively press the inner sides of the first connecting portion 141 and the second connecting portion 142 to prevent the injection molding material from entering the interior of the battery housing 1 due to gaps.

[0123] S500: Preheat the injection molding die 4.

[0124] S600: Heat and melt the injection molding material and then inject it into the injection molding die 4.

[0125] As Figure 11As shown, after the mold is closed, a plastic filling area 43 is formed between the upper mold 41 and the lower mold 42. The plastic filling area 43 surrounds the connecting portion 14 of the battery case 1. The injection molding material is injected into the injection mold 4 to fill the plastic filling area 43. After the plastic is filled, pressure holding is performed to fully fill the first groove 15 on the connecting portion 14 and the second groove 131 on the partition plate 13 with plastic. The pressure holding pressure is preferably set to 30 Mpa to 300 Mpa, more preferably 120 Mpa to 180 Mpa. The pressure holding time is preferably 2 seconds to 6 seconds. Finally, after the mold temperature drops, the mold can be opened.

[0126] Those skilled in the art can understand that although some of the embodiments described herein include certain features included in other embodiments rather than other features, the combination of the features of different embodiments means that it is within the scope of the present application and forms different embodiments. For example, in the claims of the present application, any one of the claimed embodiments can be used in any combination.

[0127] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. A method for processing a battery case, characterized in that, It includes the following steps: Step 1: Set a first groove at the connecting part of the battery case. Step 2: Injection mold on the connecting part to form a plastic frame that is partially received in the first groove and covers the outer end face of the connecting part.

2. The method for processing a battery case according to claim 1, characterized in that, Step 1 specifically includes: Set a first groove at the connecting part of the battery case by laser.

3. The method for processing a battery case according to claim 2, characterized in that, At the same time as Step 1, the processing method further includes: Clean the dust generated on the connecting part.

4. The method for processing a battery case according to claim 2, characterized in that, The battery case includes a first outer shell, a partition board, and a second outer shell arranged in the thickness direction. The connecting part includes a first connecting part provided on the first outer shell and a second connecting part provided on the second outer shell. Step 1 specifically includes: Set a first groove on the first connecting part and / or the second connecting part by laser.

5. The method for processing a battery case according to claim 4, characterized in that, Before, after, or at the same time as Step 1, the processing method further includes the following steps: Set a second groove on the partition board by laser for receiving part of the plastic frame.

6. The method for processing a battery case according to claim 4, characterized in that, Before Step 2, the processing method further includes the following steps: Fix and connect the first outer shell, the partition board, and the second outer shell by laser spot welding.

7. The method for processing a battery case according to claim 1, characterized in that, The depth of the first groove is any value from 10 microns to 290 microns; and / or, The width of the first groove is any value from 20 microns to 200 microns; and / or, The first groove forms a ring along the circumferential direction of the battery case; and / or, The number of the first grooves is multiple and they are spaced apart.

8. The method for processing a battery case according to any one of claims 1 to 7, characterized in that, Step 2 specifically includes: Put the assembled battery into an injection mold. Heat and melt the injection material and then inject it into the injection mold to form a plastic frame on the connecting part of the battery case.

9. The method for processing a battery case according to claim 8, characterized in that, Before the step of "heating and melting the injection material and then injecting it into the injection mold", the processing method further includes: Preheat the injection mold.

10. The method for processing a battery case according to claim 8, characterized in that, The step of "heating and melting the injection material and then injecting it into the injection mold" specifically includes: Inject the molten injection material into the injection mold in a high-pressure jetting manner.

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